Perforator grinding fixture



s t. 14, 1948. E KERT 2,449,459

PERFORA'I'OR GR INDING FIXTURE Filed March so, 1946 :s Shets-Sheet 1 mmvrok.

flan/are [ale/f BY M Z T. ECKERT PERFORATOR GRINDING FIXTURE Sept; 14, 1948..

3 Sheets-Sheet 2 Filed Mal ch 30, 1946 INVENTOR. 'T/Ieodare fare/f BY M Sept. 14,1948. 2,449,49

PERFORATOR GRINDING FIXTURE y Filed March 30, 1946 3 Sheets-Sheet 3 INVENTQR.

BY %MMZ% Hz; firwmay.

Patented Sept. 14, 1948 PERFORATOR GRINDING FIXTURE Theodore Eckert, Lincolnwood, Ill., assignor to. Hal-lg Manufacturing Company, Chicago, 111.

Application March 30, 1946, Serial No. 658,529

2 Claims.

will be highly efficient in use and economical in manufacture.

Among the salient objects of the invention is the provision of a fixture for holding a perforator tool in grinding relation with respect to a grinding wheel for shaping the tool to the desired form wanted for the perforating operation. It is aimed to accomplish this object by a fixture which is simple in construction, of easy operation, and capable of mounting upon the table of a grinding machine in a manner such that the operator may with the maximum degree of accuracy grind the tool to the desired form.

A still further and equally important object of the invention is the provision of means afiording mounting of the tool in the fixture with the minimum degree of effort upon the part of the operator.

In grinding a perforator tool t the proper shape or configuration, the tool must of necessity be turned in different positions about its long axis. hand or upon a rest, with the tool in contact with the grinding wheel, the result is invariably a configuration which in spots is distorted, broken down, or uneven. By the use of the fixture embodying this invention, the tool is not only securely held in place during the grinding operation, but it is also capable of being revolved or rotated to bring the surfaces thereof into contact with the grinding wheel so that the surfaces may be properly ground to conform to the desired configuration. For example, it may be desired to bevel the long edges of the tool, or it may be desired to round these edges or otherwise grind them to a shape to conform to the desired shape of the perforation. By the use of my fixture, the perforating tool may, with the minimum degree of effort on the part of the operator, be revolved into any one of a number of positions to grind the tool to a proper shape or configuration.

A still further and equally important object of the invention is the provision of a gauging device to facilitate grinding or beveling the edge of the perforator tool to a desired degree and which gauging device may be optionally operated during the grinding operation.

Other objects will appear hereinafter.

The invention consists in the novel combination and arrangement of parts to be hereinafter described and claimed. a i

If this is done by holding the tool in the The invention will be best understood by reference to the accompanying drawings showing the preferred form of construction, and in which:

Fig. 1 is a plan view of the perforator grinding fixture embodying the invention;

Fig. 2 is an elevational view of the same;

Fig. 3 is an elevational view of the same opposite to that shown in Fig. 2;

Fig. 4 is a sectional detail view taken substantially on line 44 of Fig. 1; V

Fig. 5 is a sectional detail view taken tially on line 55 of Fig. 1;

Fig. 6 is a fragmentary sectional detail view taken substantially on line 6-6 of Fig. 1;

Fig. 7 is a fragmentary sectional detail view taken substantially on line 1-1 of Fig. 5.

The several objects of my invention are accomplished by the preferred form of construction shown in the accompanying drawings.

In this connection, my improved perforator grinding fixture includes a base plate Ilfl which is adapted to be mounted upon a magnetized table of a grinding fixture and held firmly thereby in proper grinding relationship with respect to the grinding tool or Wheel.

This base plate III has extending upwardly therefrom a mounting plate I l within which there is mounted a tool holding mechanism now to be described, This mounting plate I I has its central portion removed to provide a transverse opening I2 within which is rotatably arranged an index plate IS, the peripheral edge of which is provided with a plurality of teeth It for reasons hereinafter set forth. Projecting through this index plate I3 are bolts I5 which connect a back plate l6 to a face plate l1, the peripheral edge of which is provided with a rib l8 and the sides iii of which rib are undercut to provide opposite dovetailed grooves. This faceplate IT is provided with a vertical recessed portion l9, and this face plate I! provides, together with clamping plates 20, opposite parallel vertical grooves 2| which are adapted to receive the rib portions 22 of a work holder generally indicated at T, the said plates 20 being secured to the face plate I! by screws 20'.

The work holder comprises a vise structure 23 comprising a bed plate 24 having an inner end portion 25 providing the rib portions 22 hereinbefore referred to. This bed plate 214 has a V-shaped valley 26 formed in its top surface, and in which valley the tool 2'! to be ground is positioned. The outer endportion E of the bed plate 24 is reduced as at 28 for reasons which substanwill be more apparent hereinafter.

-locating blocks 33.

limiting or locating blocks 33.

On each side 29 of the bed plate 24, there are provided spaced parallel grooves 38 and 3| to receive the inturned end portions '32 of a holding yoke 33. This yoke 33 provides a clamping screw 34 having a head 35 provided with a finger bar 36 whereby to facilitate screwing the clamping screw 34 relative to the yoke 33 against the tool 21 to -be ground.

In Fig. Zytheinturned ends '32 of the yoke 33 are shown mounted in the upper of the grooves 3|. Should a tool of relatively short height or width be placed upon the bed plate 24, in order to bring the clamping screw 34 into contact therewith, the end portions of the yoke 33 may he slid out from the grooves 35 and mounted in the respect to the mounting plate II and in order to provide means for limiting the rotation of the work holder T, I provide suitable limiting or These blocks 33 comprise complementary sections 53 secured together by means of bolts AI and providing together a dovetailed groove 42 adapted to'receive the rib i8. Cooperating with these limiting or locating blocks '39 is-a' blocking pin d3, more clearly shown in Fig. .6. This pin 43 is slidable in a transverse.

opening 44 formed in the mounting plate i l and is provided with a groove lextending longitudinally of the pin 43. Engaging in this groove 45 is the stud 46 of a set screw ll, the arrange- --ment'-'beingsuch that the set screw il may be utilized to-clamp the blocking pin 43 in an operative'position in the path of movement of the On the other hand, when it is not desired to employ the limit- -=ir 1g or locating blocks 39, the pin 43 may be projected through the opening 44 out of the path -of the blocks Bil-and be clamped in this inoperative position by the set screw '41.

To complete the work holder T, I provide at the inner end .portion thereof a recess .43, which recess is adapted to accommodate the head 49 oftheperforating tool being subjected to the grinding operation.

In Figs. 5- and '7, I have illustrated a latch structure for latching the index plate l3 against tion. Any form of latching means may be em- :ployed for this construction, but for the purpose of this disclosure the present latching means comprises a'latch bolt 55 having a tapered end portion 5| adapted to fit in the space between adjacent .teeth of the teeth It as shown in Fig. ,5. Thislatch'bolt 58 is projected in such position by means of an expansion spring 52 embracing the shank53of a head-bearing screw 54, thescrew '54 being threaded into the latch bolt 53% at 55. This spring 52 is seated in a counterbore'58 formed in the bolt 55 and the upper end portion thereof bears against a plug 5i threaded into the upper end portion of the opening 58 in which the latch bolt 55 operates, the opening 58 being formed in the mounting plate II. This plug 51 on opposite sides of the shank in the transverse notches 59 provided by the plug 51. On the other hand, when it is desired to release the index plate l3 for free rotation, the latch bolt 50 is moved outwardly relative to the mounting plate H against the action of the spring 52 so as to permit partial rotation of the shank 53 to dispose the ends of the crossbar 6B -in.--the notchestfi, whereby to releasably latch jthe latch ..,boltl5ii from'engagement with the index plate 13, thereby permitting the index plate l3 to be rotated freely by manipulation of the handle 38.

-It is intended that the adjacent center lines between the teeth be equivalent to 1 degree of example, should itbe desirable to bevel the edge abircle, .so that the index plate [3 may be rotated through any number of degrees of a circle. For

=p1ate-l3-will be latched through the medium of the latch bolt 59.

In using the perforating grinding fixture as illustrated in the drawings and as described hereim-the -yoke"33..is elevated with respect to the thereof positioned in the recess 43. The clamping ,screw1-34 is then manipulated through the :fingerbari36 tobear-down upon the work 2'? and ,firmlyclampthe' work 21 upon the bed plate 26.

Thezfixture is now moved in position to engage the grinding wheel and, if required to bring the 1worki2l 3111130 grinding operation with respect to 'sthe grinding-wheel, the work holder T may be adjusted Vertically with respect to the clamping plates Nandnlamped ina proper elevated position with respect to the grinding wheel.

Assumingthat itis required to round the op- ;rposite "long .edges of the work 21, to accomplish this operation the operator releases the index plate zl3 for free rotation and by manipulating the handle (id-rotates the work holder about its axissoas to bring into operative relation with qthegrinding wheel the edge to be rounded.

Assuming-that it is desirable to taper the long edge :of the tool 2'! at a predetermined degree, the operator in such case will then adjust the index plate to the desired degree, latching it .111 that adjusted position by means of the latchbolt 55. in thegrinding operation, the rotation 141861130 :which my improved perforated rinding fixtu e may b Pu From the .descriptionherein, taken in connec- .-tion with the accompanying drawings, it will be seenthat-the fixture is of a simple construction,

of-easy operationand that it affords the maxiaccuracy in theshaping or grinding of the perforating tool.

"While'I'have illustrated and described the preferred'form of construction for carrying my invention into effect, this is capable of variation and modification-without departing from the spirit of the invention. I, therefore, do not wish to be limited-to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A perforator grinding fixture including a base plate for mounting the fixture on the table of a grinding machine, a mounting plate extending upwardly from the base plate and having a transverse opening formed therein, an index plate rotatably mounted in said opening, a face plate secured to said index plate, a back plate secured to said index plate, a work holder adjustable relative to said face plate, a handle on the back plate for rotating said index plate and said work holder about an axis transversely of said mounting plate, means for limiting the degree of rotation of said index plate and said work holder, said last-named means including limiting blocks adjustably carried by the face plate and a blocking pin movably carried by the mounting plate and movable into the path of movement of said limiting blocks.

2. A perforator grinding fixture including a base plate for mounting the fixture on the table of a grinding machine, a mounting plate extending upwardly from the base plate and having a transverse opening formed therein, an index plate rotatably mounted in said opening, a face plate secured to said index plate, a back plate secured to said index plate, a work holder adjustable relative to said face plate, a handle on the back plate for rotating said index plate and said work 6 holder about an axis transversely of said mounting plate, means for limiting the degree of rotation of said index plate and said work holder, said last-named means including limiting blocks adjustably carried by the face plate and a blocking pin movably carried by the mounting plate and movable into the path of movement of said limiting blocks, and means for latching said index plate and said work holder against rotation relative to said mounting plate.

THEODORE ECKERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 512,545 Gilman Jan. 9, 1894 864,546 Lange Aug. 27, 1907 978,851 Crowther Dec. 20, 1910 1,377,884 Heryngfel et al May 10, 1921 1,585,706 Hanson May 25, 1926 1,698,807 Willhauck Jan. 15, 1929 2,194,089 Johnson Mar. 19, 1940 2,214,166 Hertlein Sept. 10, 1940 2,351,246 Walling June 13, 1944 2,352,489 Melin June 27, 1944 FOREIGN PATENTS Number Country Date 22,867 Germany June 25, 1883 162,774 Great Britain May 2, 1921 

